Maxiem Geldhof enhanced the grafana/cog repository by implementing covariant TypeVar support in the Builder Template, focusing on improving type relationships and safety for generic builder patterns. Using Python and leveraging skills in generic programming and type hinting, Maxiem adjusted the builder’s contained type to align with covariant expectations, which addressed a specific covariance-related issue and reduced the risk of type mismatches. This work stabilized downstream usage and made future refactoring safer and more maintainable. The changes clarified generic usage within the codebase, improved developer ergonomics, and contributed to the long-term extensibility of builder-related components in the project.